s1392

Alright zilvians, i'm in need of some major help please. I have a 1992 240sx fastback with a dohc engine that I got from another zilvian. I was told the motor had about 110k miles on it and it was sitting for about 2-3 years in the car without being used? not sure.

and yes, I did search and I mean really SEARCH!. I almost read any forum out there that has to do with failing smog.

But anyways, long story-short. I basically did everything I could. The best I got it down to, is 15mph fail with high nox and hc. But 25mph passes pretty good.

This is the list of what I've done:

New NGK ix iridium Spark plugs
New Bosch Spark plug wires
New z32 tt Fuel filter
New Bosch o2 Sensor
New OEM distributor Cap and Rotor from Nissan
NEW CATCO CATALYTIC CONVERTER!! CA LEGAL (this made me pass the 25 mph test)

Also, tried doing some of the smog tricks by (Honestly, I literally drove the car for 30+ mins before each smog)

Retarded timing all the way. it does better at 20btdc

Seafoaming through crankcase, brake booster, gas tank (didn't work)

1 whole can of B-12 chemtool through the brake booster hose (didnt work)

Sparying carb cleaner through throttle body (didn't work)

Denatured alcohol (2x times) first time didnt really do much. 2nd time it reduced about 1,000 from my nox (2800 to 1800)

and yes last but not least. I took out my whole egr system and clean it really good with brush wire and brake cleaner. Meaning, the egr valve, egr tube, egrc-bpt valve. I also, cleaned the egr port from that little hole on top of the throttle body with a long wire brush and carb cleaner. (replaced all hoses when I first got engine).

Current results:

@ 15mph
Co2: 14.7 o2: 0.4
HC: max = 83. meas = 133 = fail
CO: max = 0.75 meas = 0.23
NO: max = 559 meas = 1820 = fail

@ 25mph
Co2: 15.3 o2: 0.0
HC: max = 65. meas = 56 = pass
CO: max = 0.63 meas = 0.07 = pass
NO: max = 516 meas = 514 = barely pass lol

so please anyone out there that had this similiar problem or anyone with some advice please help. i'll grealy appreciate. thanks

Only problem I know of my car right now, is that I have a sticky valve lifter ticking sound. (I think)

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car-dash'n-em

Def

You're so close, just seems like an aftermarket cat that's not quite up to snuff. Will it pass a visual if you weld in a 2nd cat? I'm willing to bet that'd pass it.

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S13 Hatch - Goes around tracks quickly
DEFSPORT

s1392

im pretty sure the guy would do me a favor and look away for visual test. but the thing is, the muffler shop took my old cat and left me with the catco. and its pretty expensive to get another one =(. im tired of loosing money on parts

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car-dash'n-em

HiddenCharacter

This stuff helped me pass with 2 different cars:

Amazon.com: CRC 05063 Guaranteed To Pass Emissions Test Formula - 12 Fl Oz.: Automotive

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HiddenCharacters Crew

s1392

you posted the same thing in some other thread, lol. but i havn't tried it. I tried RESTORE fuel system treatment and it didn't help lol. How exactly did you use it? Just pour directly into gas tank and fill up with gas?

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car-dash'n-em

Nickys13

If you don't have the money to fix the problem pay someone to pass it for you It'll be cheaper. I payed $700 so that my car could pass legally, well that was a stupid mistake when i should have payed $150-200.

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s1392

I know a couple of ppl that would do it for 200-250. But thats kinda too much for me. I still wana know the reason why my nox is so high at 15mph, and possibly could be a cheap fix. Not only, i did so much to the car so I wana finish it off the legal way lol. But thnx for the input

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car-dash'n-em

s1392

Actually I smogged 6 times.... Lol.. Failed so many times i forgot how much i failed. Anyway, I scanned all of the actual results from the first to current.

Here it is ...

It's wierd, that my first result of smog the nox wasn't that high compared to other results, at THAT TIME i didn't even touched the engine. It had the 3 year old spark plugs and wires, fuel filter, dirty egr, old cat conv. so wtf? is it that the new parts made the car burn more gas which caused it to run rich? idkkkkkkkkkkkkk FML

it seems that it just got worse and worse everytime I tried something until I got a new cat. it helped a bit.

Attached Images

	1st smog 001.jpg (286.4 KB, 37 views)
	2nd smog 001.jpg (113.8 KB, 23 views)
	3rd smog 001.jpg (210.4 KB, 19 views)
	4th smog 001.jpg (211.4 KB, 19 views)
	5th smog 001.jpg (207.9 KB, 19 views)
	6th smog 001.jpg (206.4 KB, 30 views)

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car-dash'n-em

HiddenCharacter

Yeah pretty much, if I remember correctly your supposed to pour it into a full tank and run it all the way out so that it has enough time to cycle through your system and clean the carbon deposits etc.

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HiddenCharacters Crew

s1392

I tried looking in o'reillys for that cleaner. Couldn't find it. Can it only be bought from amazon? I'll try looking into other auto stores.

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car-dash'n-em

mxexux

HC = unburned gas or oil = most likely car is miss firing at low RPM

NOx = high combustion temps = EGR is not doing its job well

Put these thing together + your results with failing on the low speed test, I would take an educated guess and say that you could have a vacuum leak somewhere coupled with a faulty EGR system.

First, I would replace all the vacuum lines with new one; vac hose is pretty cheap.

Second, I would check the EGR system thoroughly. I think there was a really good write up on how to clean out the tube somewhere on this forum.

Hope this helps. Good luck

s1392

thanks for the reply. I did replace all of the egr vaccum lines that are near the firewall with new ones. Maybe i have a vac leak else where?

Also, once the egr is lifted manually with my finger the motor would stall out. Maybe i didnt clean good enough? i sprayed the shit out of it with brake cleaner.

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car-dash'n-em

Krewlkid

Heres your answer, the egr system seems like its working, the intake has its own runner for the egr that is very easily plugged its self.

Note: this is a single cam manifold but the plugs and cleaning are the same


Remove all plugs in intake manifold

check to see how pluged the system is

in this case, complete plugged

clean it all out and pass smog flying colors!


quite a few people have come directly to me for legit smoging of 240sx and other various problem vehicles.


Ca Emissions Specialist
Gold Shield Station
Customer Assistance Program Approved

s1392

Wow, this is one of things that i havnt done and hopefully this is the problem that I am having. Thanks man! Ill get started on this as soon as possible when i get my day off on monday.

Just a stupid question, don't you think if it was clogged, I should be failing both 15 and 25 mph tests?

But still tho ill try cleaning!

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car-dash'n-em

S-Nation S13

thats is what i did and i passed!!!

s1392

you cleaned all the runners? I have to take off the upper intake manifold to get to it, right?

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car-dash'n-em

s14j

i had similar problem. turned out that the O2 wire was just old and messed up. so the sensor would ground it self although i dint get a CEL. it passed 25 but wouldn't pass 15. because the wire sits behind the motor is gets all messed up. when i checked it it was shorting and grounding its self fixed it and it passes.

all i did to pass was 91 oct
ran it for about a hr and dint turn it off when i was there.
spark plugs oil change
also just sprayed carb cleaner through different vacs.

good luck.

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95 s14 ka DD

andisan

check all of your emission components, make sure theres no rust or carbon build up, Mine didnt pass and they had to replace that emission thing next to the exhaust manifold, but after i checked it out, it was because the vacum hose connection was clogged up :/, thats why they said i needed a new one if only i would of just checked and cleaned all of the parts i would of saved time and money.

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s1392

I think this may be the problem! Because my o2 wire seems a little melted from touching the exhaust manifold. Ill definitely try it out once I have time. How exactly did u ground it? Thanks

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car-dash'n-em

s1392

Do you know what part exactly? I might just have to setup a date to take all of my emmission componens apart and clean them thoroughly

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car-dash'n-em

s14j

i just cut the wire to the o2 from there it was melted. the problem was that the wire is warped in copper wire and it had cut threw at a point and started touching the wire that was the direct signal wire for o2 causing is to not read correctly although the ecu did know it was there.

I made the wire longer so it wouldn't be so close to the exhaust mani


best thing u can try before you cut is get a voltage meter and check.
read up and check voltage reading for the o2
hope its the right o2 your using as well.

another thing is check that your egr is not leaking.

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95 s14 ka DD

wangan_cruiser

did you go to the same shop and fail all the time? problem could be the shop too. shit it happened to me. i did all the suggested cleaning from google/forum ( i do my research ha) and still failed 4x. then i got frustrated and went to another shop and i did passed with only 1st try.

coupesallday!

I have a 1991 coupe dualcam and it failed smog bcuz the timing was advanced (27) and there was a vacuum leak,and it was running rich. but the engine was rebuilt to oem spec and the o2 sensor is brand new.

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s1392

Thanks s14j, I'm gonna started on that tmrw. But yea I do go back to the same fucking smog shop everytime i fail. Only reason i go back, is because he lets me do free retest's but it seems like he fails me on purpose. That jerk has a smile on each time I fail lol. I'm gonna go back there one more time after I do all this cleaning and inspecting and if I fail I'm going to some other shop for sure lol

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car-dash'n-em

s1392

Well I got some bad news... just smogged my car again after taking off the whole intake manifold and cleaned it really good and I mean REALYY GOOD with 3 bottles of brake clean, all the ports and everything.(intake manifold wasn't even that clogged lol). Also, the pcv hose under the manifold was broken. Replaced the hose and cleaned the pcv box with gasoline. After all that I went to smog at a different shop to see if it would be any different and still failed with nox at 1600. 25 MPH passed like always.

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car-dash'n-em

s1392

sorry to bump this thread.. but i wanna post the issue that I was having with my kade failing smog, so maybe others can get an idea. It was a bad maf and leaky injector on cylinder #1. Replaced injector with used one and had all my injectors machined cleaned. Also, replaced my maf from another kada motor. Took it for smog and it passed!! =]

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car-dash'n-em

WIKID S4TEEN

^ Wow, 6 months later, lol.
+A for you not giving up and coming back to post for others!

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FRpilot

seems like you did almost everything to pass smog.

i subscribed to this so i can follow your procedures as blueprint when my s13 fails smog.

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moto moto

i am having this same problem right now. first time it failed smog shop said i needed a cat so i replaced the cat. went to another shop and failed. they told me i need to replace my egr valve. so i need to replace that now

2tonecoupegrl

What made you decide to take another maf and try?

Glad you got her all up and running the way it should now and passed

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